This invention relates to a method and apparatus for Voice over Internet Protocol (VOIP) communications, and more particularly creating multiple VOIP call sessions for a single directory number. While the invention is particularly directed to the art of VOIP, and will be thus described with specific reference thereto, it will be appreciated that the invention may have usefulness in other fields and applications.
A Directory Number (DN) is a telephone number, an example of which can include a phone number from the North American Numbering Plan (NANP), among others, which identifies a terminal, such as a cell phone, softphone, etc., or a location in the case of conventional Plain Old Telephone Services (POTS) telephones, for routing calls to and from the terminal/location over the Public Switched Telephone Network (PSTN). When a calling party attempts to communicate with a called party, the calling party dials the called party DN and the call is routed from the calling party terminal to the called party terminal using called party DN. The calling party DN is also used during the call to establish a return route back to the calling party terminal thereby providing a duplex call session giving simultaneous two-way communication between the two terminals.
VOIP calling uses Internet Protocol (IP) addressing schemes to provide packet switched voice communications over a packet data network such as the Internet. Rather than establishing a physical connection between the two terminals as is done with Plain Old Telephone Switched (POTS) circuit-switched calls, or using specialized packet-switched networks as is done in ATM and others, VOIP uses an IP address for routing packet-based information to and from a VOIP terminal over the Internet to provide voice communications referred to as a call.
In order to communicate with terminals over the PSTN, a VOIP terminal IP address is associated with a DN and the conversion between the two is made in the communications network. Currently, each DN capable of providing a VOIP call session via a VOIP terminal has one IP address associated with it at the communications network level. As a result, only one VOIP call session is allowed for each DN by the communications network. If the DN is in use by a VOIP terminal engaged in a VOIP call session, then a “busy” signal is created and sent back to another calling party who tries to call the VOIP terminal using the DN.
If several VOIP terminals are associated with a single DN, similar to having several land line telephones connected to the same phone line, a local router is used to connect the VOIP terminals with the IP network. The DN is then associated with the IP address of the local router. Again, only one VOIP call session at a time is allowed by the communications network for the DN associated with the router's IP address. Even though multiple parties may be bridged together by the network to simultaneously communicate with the VOIP terminal, this still only constitutes a single call session for the DN. As a result, while one VOIP terminal in this configuration is used in a call session, another call cannot be made or received simultaneously on one of the other VOIP terminals connected to the local router associated with the same DN.
The present invention contemplates a new and improved system and method that resolves the above-referenced difficulties and others.